Generally, devices such as televisions, video players, digital versatile disc (DVD) players, and set-top boxes can be remotely controlled with a remote controller provided thereto. Such a remote controller has various keys or buttons to activate the functions of the device. Besides, there have been proposed technologies to improve the operability of a device such as a remote controller and a mobile phone in the dark or the like by providing a backlight (key backlight) that illuminates the keys from behind.
Operation keys on the remote controller can be classified into main keys that are mainly used and subkeys that are used for specific purposes. In the case of this key arrangement, in view of space-saving and design, subkeys are generally provided as being covered with a cover or the like and the cover is opened when they are used. The conventional remote controller is configured such that only the main keys are illuminated, or the main keys and the subkeys are illuminated at the same time. Accordingly, some keys may be unnecessarily illuminated, which may result in wasteful power consumption.